You would be surprised if he has gathered quite the army he had last time- that was after a big manhunt, and in fact it was only that many because they were looking for Kuylen.
Still, if a team is eight (seven and a Captain), he probably has at least one team for each of you. You wouldn't want to fight it out.
As to the source... no.
Because Doon set us up.
As to the surprise - Rah stopped us falling for his ambush by knocking Tanic on the head.
Erm, Rex, you realise that if we leave Rand on the ship and use it as a distraction to get to Helkin, there will still be the entire Osokan force between us and the ship, and potentially on the ship as well... But, I don't have any other ideas.